The invention relates to a water-resistant undercast sleeve. In this application, the term “stockinette” is used to refer to prior art structures that are applied directly to the skin. In conventional casting practice, a stockinette is first applied to the injured limb to reside directly against the skin of the patient. The stockinette is usually formed of a thin circular-knit product that has sufficient stretch to allow it to fit onto the limb and closely conform to the varying shapes, contours and dimensions of the limb without wrinkles, overlaps or puckers that could cause discomfort or abrasion to the skin.
A padding is then applied over the stockinette onto the injured limb before the application of the cast tape. The padding provides a cushion and spacing between the skin and the cast tape, and protection to the bony prominences of the limb, and further aids in patient comfort. The stockinette and padding together form a system that collectively provides protection to the limb while the overlying cast tape provides the necessary support and rigidity to immobilize the limb during healing.
However, the conventional stockinette and padding system is not resistant to perspiration and/or moisture and when wet can give off odor and become uncomfortable to wear. This leads to a higher incidence of skin irritation and maceration, and in many instances may require removal and replacement of an otherwise medically effective cast. These factors have traditionally provided the majority of complaints regarding what is otherwise a medically-sound and cost-effective treatment regimen for bone fractures and other conditions requiring extended immobilization of a limb.
The invention described in this application discloses an undercast sleeve, which will replace both the conventional stockinette and padding. In addition to providing a satisfactory level of cushioning, this sleeve also repels water and dries quickly when wetted. The water-resistant sleeve of this invention is aimed at providing more freedom to the patient and help them carry out daily routine activities with much ease. Similar efforts have been conducted in the past to develop a water-resistant undercast sleeve, as described in U.S. Pat. No. 5,540,964 and WO2005/004765. However, none of the efforts have resulted in a successful working product.
The '964 patent discloses a sleeve constructed using hydrophilic fibers with an applied hydrophilic finish. The recited principle is to wick moisture away from the skin. However, the cast material itself is relatively impervious to both air and moisture transfer, so the wicking action moves the moisture into the overlying padding and cast material, where it accumulates in the padding and in the structure of the cast.
The WO '765 publication discloses a sleeve using microdenier fibers to wick moisture away from the skin, but this product has not proven effective for reasons similar to the '964 patent.
In contrast to these prior art attempts to solve the moisture-retention problem with hydrophilic products, applicant has discovered a means of utilizing hydrophobic materials to drain moisture away from the skin utilizing a combination of fabric mechanics and fiber technology.